Cat litter box

ABSTRACT

The invention concerns a cat litter box with a rotatable container  20  housed on a frame  1 , the tray floor  21  of which forms a collection tray for cat litter and the like. A cleaning rake  30  is arranged standing in the container  20  and reaching to the floor of the tray  21 , with which cleaning rake, when the container is rotated in one direction to clean it, waste matter  34 , particularly faeces, can be separated from the cat litter  29 . The container possesses a storage chamber for the separated waste matter which can be moved with the container, which chamber is formed by a bag  40 , the entrance of which is arranged above the cleaning rake  30  in the position of use. The tray floor  21  consists in accordance with the invention of a closed half shell which extends over a span area of less than 250° which with a first part shell section forms the floor of an essentially open collection tray  20 A and with the other part shell section forms the rear wall of an interim storage tray  20 B for litter, whereby the cleaning rake  30  is arranged at the transition segment  50  between the storage chamber  40  is arranged in the position of use on the side of the cleaning mechanism  30  facing the litter retention tray ( 20 B) and whereby the rotation of the container  20  from the position of use is restricted to a pivot movement of 120-180° in the one direction A.

The invention relates to a cat litter box with a rotatable container positioned on a frame. The floor of the tray forms a collection tray for cat litter, etc., with a mechanical cleaning mechanism positioned vertically in the container and reaching to the floor of the tray, with which waste matter, particularly faeces, can be separated from the cat litter when the container is rotated in one direction to clean it and with a storage chamber for the separated waste matter which can be moved together with the container, the entrance to which is arranged in the position of use above the cleaning mechanism.

A large number of suggestions exist for cat litter boxes of the prior art which are automatically or semi-automatically cleaned. Known cat litter boxes can be subdivided into two groups according to their function. The first group, which have standing containers and moving cleaning rakes, include for example DE 297 18 260 U1, EP 622 987 B1 and U.S. Pat. No. 5,226,388. Since the cleaning rakes must be moved through the cat litter when it contains waste matter, the power output to be installed for the motor and the forces exerted on the cleaning rakes are relatively high. During the raking procedure, the forces also operate on the clumps of faeces, which are bonded only by slight adhesive forces, and which, due to the design, have to be moved over relatively long distances through the clean cat litter, with the result that an undesirable abrasion of the clumps of faeces results. The drive and guidance for the cleaning rake are relatively complex in their construction, and difficult to clean and to keep clean in daily use. They severely restrict the freedom of movement of the cat. In addition, corner areas remain which cannot be cleaned or cannot be sufficiently cleaned with moving cleaning rakes.

The invention is based on the second group of cat litter boxes, which have cleaning sieves arranged standing in the container and reaching to the floor of the tray. Cat litter boxes of this type are illustrated for example by U.S. Pat. No. 4,120,264, U.S. Pat. No. 5,402,751, U.S. Pat. No. 5,507,252 and U.S. Pat. No. 5,911,194. They each have a more or less cylindrical housing which is closed all around, and cleaning is accomplished by the housing performing a complete or nearly complete 360° revolution. Cat litter boxes pursuant to U.S. Pat. No. 5,402,751 or U.S. Pat. No. 5,507,252 are thereby constructed as containers which can be rolled off on the floor, while the housings of the other cat litter boxes are housed on a frame. The mechanically simplest solution is displayed by U.S. Pat. No. 5,911,194, which forms the generic starting point.

The generic cat litter box pursuant to U.S. Pat. No. 5,911,194 possesses an upper container part linked to two vertical frame supports. The open underside of the upper part of the container is connected to a floor formed as a tray. This upper part includes an entrance opening, having a closable flap, for the cat. A cleaning sieve is situated in the interior of the container in such a way that it separates around one fifth of the volume of the container as a sector. The container can perform a 360° revolution, in which all the cat litter is retained in the interior. The cat litter falls during the revolution of the container through the lattice sieve into the separate sector, and waste matter and faeces remain on the outside of the cleaning sieve. The complete separation of cat litter and faeces is accomplished after a revolution of approximately 150° to 180°. The cleaning sieve has a closed plate part which leads into an opening, on the rear side of which a collection bag or similar is stretched as a storage chamber. Through the further turning of the container, the sieved-out faeces slip or roll through the sieve onto the plate appendage, from there into the opening, and then into the bag, while the sieved-out cat litter still remains in the separated sector. After completion of a 360° revolution of the container, the cat litter runs a second time through the sieve section of the cleaning rake, while the faeces remain behind in the bag. The interior of the bag is to the maximum possible extent sealed off from the interior of the container as a result of the arrangement of the opening leading vertically upwards. The filled bag hangs in the position of use in that section of the cat litter box in which the cat should carry out its business, and it can be exchanged through an access opening in the upper side of the container.

In the use of this cat litter box, soiling of the cleaning sieve and the plate appendage and stronger traces of waste matter in the cat litter appear after a short time. These make excessively frequent replacement of the cat litter necessary. The power output of the drive motor which is necessary for the automatic turning of the container is comparatively high because of the kinematic of the cleaning movement for the cat toilet. A further disadvantage is that the closed construction of the container does not take account of the need of many cats to carry out their toilet in the open.

The task of the present invention is to create a cat litter box which can be cleaned automatically or semi-automatically through a simple, cost-effective and low-maintenance construction, which has as high as possible a self-cleaning effect which because of an improved kinematic of the cleaning movement makes less demands on the power output of the drive motor, and which takes account of the needs of cats particularly for freedom of movement etc.

This and additional tasks are accomplished by the invention stated in claim 1. In accordance with the invention, it is foreseen that the floor of the tray consists of a closed half shell which extends over a span area of less than 250°, preferably over 135-230°, which, with a first part shell section, forms the floor of an essentially open collection tray and with the other part shell section, forms the rear wall of an interim storage tray for the litter, whereby the cleaning mechanism at the transition segment is arranged between the part shell sections, whereby the storage chamber in the position of use is arranged on the side of the cleaning mechanism which points to the litter retention tray, and whereby the rotation of the container from the position of use is restricted to a pivoting angle of 120-180° in one direction. With the solution in accordance with the invention, a cat litter box is therefore proposed which provides the cat with an open tray area for its use as a toilet which is not covered by a roof or by an over-spanned ceiling, and which because of the rotatability, the displaced interim storage tray for the litter and the mechanical cleaning mechanism positioned between the open collection tray and the interim storage tray for the litter, can be cleaned by an automatic or semi-automatic swivel movement of the container. During a cleaning swivel movement, the cat litter is lead across the cleaning mechanism into the interim storage tray for the litter, whereby the waste matter is sieved out of or taken up from the cat litter at the cleaning mechanism. The entrance to the storage chamber, which is directly situated next to the cleaning mechanism, guarantees that the sieved-out waste matter travels the shortest possible distances to the cleaning mechanism, so that there is no abrasion of the waste matter on the inner wall of the tray floor and/or on the sieve surface of the cleaning mechanism which could contaminate the cat litter. A further advantage is that, because of the restricted swiveling movement and the tray sections arranged offset to each other, the relatively heavy cat litter is only moved and lifted up over a short distance, so that a drive motor of low power can be used.

In the preferred design, the collection tray and the interim storage tray for the litter are arranged roughly at right angles to one another, and intersect in a transition segment. This construction minimizes the volume required by the cat litter box, because the transition segment is both a component of the first partial shell section, which forms the collection tray, and a component of the partial shell section that forms the interim storage tray for the litter.

With the preferred method of construction in accordance with the invention, the entrance to the storage chamber is closed when in use, and can be automatically or manually opened during the cleaning movement. This design has the advantage that there is no cause for concern with regard to the odor inconveniences from the waste matter, which is sieved-out and contained in the odor-tight closed storage chamber in the position of use. It is particularly preferable for this purpose if the storage chamber is constituted of flexible material, particularly of a bag or the like, and/or if the entrance to the storage chamber extends over the whole container width or the width of the cleaning mechanism. The use of a flexible bag makes it possible to dispense with closure flaps for the entrance to the storage chamber. Where the storage chamber extends across the whole width, centering guide plates or the like which could become soiled by the moving waste matter during the swivel movement are also unnecessary. As well as this, the flexible bag can be arranged in such a way that it extends as far as directly next to the cleaning mechanism, so that all areas of the cleaning chamber that come into contact with waste matter can be replaced when the bag is replaced.

A mechanically simple and cost-effective solution for the openable and closable entrance is achieved in accordance with the invention by arranging two cross strips, which, in the position of use, lie one on top of the other, at the entrance to the flexible storage chamber. One of these strips is free and extends beyond the side pieces of the container, and the other can be moved together with the container. The side pieces of the container can then preferably possess a drive lug for the free cross strip and the upper sides of the side walls of the frame can form a guide path with a limit stop for the free cross strip, whereby the limit stop operates together with the free cross strip during the cleaning movement and accomplishes a relative movement between the free cross strip and the other cross strip which opens the entrance and whereby the drive lug positively returns the free cross strip to the starting position in a swivel movement in the opposite direction. In order to maximize the sealing effect at the entrance in the position of use, the free cross strip can preferably be raised from the guide path in the position of use of the cat litter box by means of the other cross strip. The solution described above in accordance with the invention accomplishes the opening and closing exclusively by positive forming and by gravity during the rotary movement.

Additionally suited to the purpose, the rotation of the container from the position of use is restricted to a pivoting angle of some 10-50° in the direction opposite to the swiveling up direction, so that the cat litter is again distributed essentially horizontally in the collection tray at the end of the cleaning process. In the simplest design of the cat litter box in accordance with the invention, the cleaning mechanism is formed by a cleaning rake with slit openings between cleaning struts. In accordance with the intention, the cleaning rake is then fastened in guides fitted to the interior walls of the side pieces from which it can be released, enabling it to be cleaned as the case arises or replaced with another cleaning rake. In addition, the interim storage tray for the litter and the interior wall of the collection tray can be well and simply cleaned when the cleaning rake is removed.

The swiveling movement of the container can either be accomplished by hand or be motor-driven, whereby with the motorized drive in particular, the restriction of the swiveling movement can be effected by the circuitry of the motor. In the preferred design of the cat litter box, the container can be housed in a sub-frame on roller guides and can be driven by a motor, with the rollers of the sub-frame being housed on the side walls of the frame, engaging in guide paths which are formed by beveled recesses with open rims on the side pieces of the container and transferring the working surfaces for the rollers opposite the tray floor to the axis of rotation.

Further advantages and designs of the cat litter box in accordance with the invention arise from the following description of a design example illustrated diagrammatically in the drawing. In the drawing:

FIG. 1 gives a perspective view of a cat litter box from the front;

FIG. 2 shows a vertical section through the cat litter box from FIG. 1 in the position of use; and

FIG. 3 shows the cat litter box in a pivoted position at the return point of the cleaning swiveling movement, as a cutaway in accordance with FIG. 2.

The cat litter box indicated in FIGS. 1 to 3 as an entirety with 10 possesses an essentially rectangular sub-frame 1 and a rotatable container 20 housed in this. The sub-frame consists of a floor plate 2 and two frame side pieces 3 and 4 which are welded or screwed to this and joined by cross pieces not shown, to the inner sides of which rollers 5 and 6 are attached for the rotatable housing of the container 20.

The container 20, which is constructed in the nature of a semi-cylinder arranged horizontally, possesses a tray floor 21 which extends essentially as half shell or a semi-cylindrical shell over a span area of about 230° between the left lower tray floor end 22 in FIG. 2 in the position of use and the right upper floor tray end 23. Near the lower tray floor end 22, the tray floor 21 itself diverges in the design example shown from the cylindrical shaping and is provided with a front plate 24 which in the position of use stands obliquely and a straightened floor section 25 which extends to the driver roller 7. The rollers 5 and 6 and the drive roller 7 engage with the container 20 in the guide paths 26′, which are shaped in each case at the transition between the side pieces 27, 28 of the container 20 and its tray floor 21 and are formed by open-rim beveled recesses 26 on the side pieces 27 and 28 of the container 20 and the tray floor 21. The guide path 26′ is circularly cambered around the axis of rotation D of the container over the whole area over which it extends. The working surface for the drive roller 7 and the guide rollers 5 and 6 is also displaced towards the axis of rotation D in relation to the tray floor 21 by the recess 26 and the recessed guide path 26′. The drive of the container 20 can be effected by interlocking with the guide path 26′ or by means of a friction covering of the drive roller 7. To drive the drive roller 7, a motor can be arranged in the sub-frame 1 and coupled with the drive roller 7, or it can be driven by hand.

The container 20 forms with its part shell section, illustrated in the position of use below in FIG. 1 and FIG. 2, which extends in front of the cleaning rake 30, forms a collection tray 20A open above for the cat litter 29, while the part shell section of the container 20 which extends vertically in the position of use constitutes an interim litter storage tray 20B with a front wall, here open. The transition segment identified as 50 in FIG. 2 forms both a partial section of the collection tray 20A for the cat litter 29 and a part shell section for the interim storage tray for the litter 20B. The lower end 31 of the cleaning rake 30, which extends to the inner wall of the tray floor 21, marks the beginning of the transition segment 50. The mechanical cleaning mechanism 30 itself consists, as can be seen from FIG. 1, of a cleaning rake with vertical struts 32 that proceed from a common cross strut which extends over the width of the container 20 between its side pieces 27, 28. The cleaning rake 30 is fastened in guides on the inner walls of the side pieces 27 and 28 in such a manner that it can be released, in a way not illustrated, and can be removed and replaced by another when necessary. With the intermediate spaces between the cleaning struts 32 of the cleaning rake 30, waste matter 34 is sieved out of the cat litter 29, which then, with a larger swivel angle, rolls under the force of gravity over one side 35 of the cross strut 32 into a storage chamber here formed by a bag 40, as explained in the following.

In order to automatically or semi-automatically sieve out the waste matter 34 which a cat leaves in the collection tray in the course of it doing its toilet, the container 20 is swiveled by a pivoting angle of 180° in direction A into the extreme position as in FIG. 3. The rotation of the container 20 from the position of use is restricted by a limit stop not shown or by the triggering of the electrical drive motor to a pivoting angle of 120-180° in the one direction A. During the continuous swiveling, the cat litter 29 falls through the intermediate spaces in the cleaning rake 30, whereby the waste matter 34 is restrained on the side 35 of the cleaning rake 30 which faces the collection tray 20A. After reaching the position shown in FIG. 3 (extreme position), the waste matter 23 rolls off under the force of gravity over the side 35 of the cleaning rake 30 and into the bag 40 forming the storage chamber, which is open in the extreme position (FIG. 3). In the position of use (FIG. 2), in contrast, the bag 40 or its entrance is closed odor-tight and the bag 40 hangs within the litter retention tray 20B. It can thereby rest on the side 36 of the cleaning rake 30, which points to the litter retention chamber 20B.

The opening of the entrance to the container 40 takes place automatically during the swiveling movement of the container 20 in direction A, while the closing of bag 40 automatically on the return swiveling movement in the opposite direction. The bag 40 thereby moves exclusively within the litter retention chamber 20B, which thus fulfils a double function and creates the free space for the storage chamber 40. In order to accomplish the automatic opening and closing during the swiveling movement without separate motors, two cross strips 41, 42 are arranged at the entry to the bag 40, of which one cross strip 41 can fall together with the cross strut 33 of the cleaning rake 30 and can be attached in an appropriately fixed location from which it can also be dismounted on the inner walls of the side pieces 27 and 28 of the container 20. The second, upper cross strip 42 lies loosely on the lower cross strip 41 and extends with the two strip ends 43 over the side pieces 27 and 28 of the container 20 and also over the frame side walls 3 and 4 (FIG. 1). The upper sides 3′ of the two frame side walls 3, 4, during the cleaning movement of the container in direction A, temporarily form a guide path for the upper cross strip 42, which is laid for this purpose over the strip ends 43 which extend beyond the side pieces 27 and 28 of the container on the upper side 3′. The upper side 3′ of the frame side walls 3, 4 run slightly diagonal to the horizontal position, falling towards the collection tray 20A, and end in the limit stops 8 which are formed by a lug proceeding upwards from the side walls 3, 4 of the frame.

In the position of use as in FIG. 2, the upper cross strip 42 lies on the lower cross strip 41 and is slightly raised in relation to the upper side 3′ of the frame side walls 3, 4, such that the clamping force at the entrance to the storage chamber 40 is determined by the weight of the cross strip 42 and the weight of the waste matter contained in the bag 40. With the progressive swiveling of the container 20 in the direction A shown by the arrow, the strip ends 43 come into contact with the upper sides 3′ of the frame side walls 3, 4, such that the distance between the cross strips 41, 42, and thus also the opening of the entrance to the bag 40 are enlarged by the further pivoting of the container 20 to the end position illustrated in FIG. 3. The upper, free cross strip 42 thereby moves across the upper side 3′ as far as the limit stop 8, without being able to pass by this. In the extreme position illustrated in FIG. 3, the faeces can fall over the second cross strip into the fully open bag 40, which extends across the whole width of the container 20. With the return swivel motion in the opposite direction, the distance between the cross strips 41 and 42 gradually becomes diminished. Some 50-30° before reaching the position of use, a drive lug 27′ on the frame side walls 27 and 28 comes into contact with the upper cross strip 42, and gradually pushes this across the guide path back to the rear. The drive lug 27′ thereby forms an approximately V-shaped notch together with the front wall 27″ which prevents the free cross strip 42 from being able to leave the guide path on the upper side 3′ of the frame side walls 3, 4. The side partial wall sections 27″, 27′″ before and behind the drive lug 27′ extend vertically in the position of use (FIG. 2). As can easily be recognized from the Figures, the side pieces 27, 28 are roughly crescent-shaped and each rise only a short distance laterally above the collection tray 20A and the litter retention chamber 20B. The V-shaped notch, the drive lug 27′, the guide path and the limit stop 8 accomplish the opening during the swiveling movement and the subsequent closing of the entrance of the storage chamber 40, likewise moved during the swiveling movement, exclusively by positive forming. The free cross strut 42 can also be moved on the same circular path B as the cross strip 41 and the cross strut of the cleaning rake, so that drive agents can be provided on the cleaning rake to form drives. 

1. Cat litter box with a rotatable container housed on a frame the tray floor of which forms a collection tray for cat litter, etc., with a mechanical cleaning mechanism vertically positioned in the tray, contained and reaching to the floor of the tray, with which waste matter such as particularly faeces can be separated from the cat litter during a cleaning movement of the container in one direction and with a storage chamber for the separated waste matter which chamber can be moved with the container, the entrance of which chamber is arranged above the cleaning mechanism in the position of use, this being characterized in that the floor of the tray (21) consists of a closed half shell which extends over a span area of less than 250°, and preferably over 135-230°, which forms with a first part shell section forms the floor of an essentially open collection tray (20A) and with the other part shell section, forms the rear wall of an interim storage tray for the litter (20B), whereby the cleaning mechanism (30) is arranged on the transition segment (50) between the part shell sections, whereby the storage chamber (40) in the position of use is arranged on the side (36) of the cleaning mechanism (30) facing the litter retention tray (20B) and whereby the rotation of the container (20) from the position of use is restricted to a pivoting angle of 120-180° in the one direction (A).
 2. The cat litter box of claim 1, characterized in that the collection tray (20A) and the interim storage tray for litter (20B) are arranged essentially at right angles to one another and intersect in the transition segment (50).
 3. The cat litter box of claims 1 and 2, thereby characterized in that the entrance to the storage chamber (40) is closed in the position of use and is automatically openable or open during the cleaning movement.
 4. The cat litter box of claims 1 to 3, characterized in that the entrance to the storage chamber (40) consists of a flexible material, particularly of a bag or the like, and that the entrance to it extends over the whole width of the container or the whole width of the cleaning mechanism (30).
 5. The cat litter box of claims 3 or 4, characterized in that two cross strips (41, 42) which in the position of use lie one on top of the other are arranged at the entrance to the storage chamber (40).
 6. The cat litter box of claim 5, characterized in that side pieces (27, 28) of the container (20) possess a drive lug (27″) for the free cross strip (42) and that the side walls of the frame (3, 4) form with their upper sides (3′) a guide path with limit stop (8) for the free cross strip (42), whereby the limit stop (8) operates together with the free cross strip during the cleaning movement and accomplishes a relative movement between the free cross strip and the other cross strip (41) which opens the entrance and whereby the drive lug (27″) positively returns the free cross strip (42) to the starting position in a swivel movement in the opposite direction.
 7. Cat litter box of claims 5 or 6, characterized in that the free cross strip (42) is raised from the guide path in the position of use of the cat litter box.
 8. Cat litter box of one of claims 1 to 7, characterized in that the rotation of the container from the position of use is restricted to a pivoting angle of around 10-50° in the opposite direction.
 9. Cat litter box of one of claims 1 to 8, characterized in that the cleaning mechanism is a cleaning rake (30) with slit openings between the cleaning struts (32), whereby the cleaning rake (30) is preferably attached in guides on the inner walls of the side pieces (27, 28) and can be released.
 10. Cat litter box of one of claims 1 to 9, characterized in that the container (20) is housed in a sub-frame (1) on roller guides and can be driven by a motor with the rollers (5, 6, 7) of the sub-frame being housed on the side walls (3, 4) of the frame, engaging in guide paths which are formed by beveled recesses (26) with open rims on the side pieces (27, 28) of the container (20) and transferring the working surfaces for the rollers (5, 6, 7) opposite the tray floor (21) to the axis of rotation (D).
 11. Cat litter box of one of claims 1 to 5 or claims 7 to 10, characterized in that drive agents are provided on the cleaning rake to move the free cross strip back to the starting position. 